org.ode4j.ode
Interface DBody

public interface DBody

A rigid body has various properties from the point of view of the simulation. Some properties change over time:

Position vector (x,y,z) of the body's point of reference. Currently the point of reference must correspond to the body's center of mass.

Linear velocity of the point of reference, a vector (vx,vy,vz).

Orientation of a body, represented by a quaternion (qs,qx,qy,qz) or a 3x3 rotation matrix.

Angular velocity vector (wx,wy,wz) which describes how the orientation changes over time.

Other body properties are usually constant over time:

Mass of the body.

Position of the center of mass with respect to the point of reference. In the current implementation the center of mass and the point of reference must coincide.

Inertia matrix. This is a 3x3 matrix that describes how the body's mass is distributed around the center of mass. Conceptually each body has an x-y-z coordinate frame embedded in it that moves and rotates with the body.

The origin of this coordinate frame is the body's point of reference. Some values in ODE (vectors, matrices etc) are relative to the body coordinate frame, and others are relative to the global coordinate frame.

Note that the shape of a rigid body is not a dynamical property (except insofar as it influences the various mass properties). It is only collision detection that cares about the detailed shape of the body.

From odecpp.h.

Nested Class Summary

static interface

DBody.BodyMoveCallBack Whenever a body has its position or rotation changed during the timestep, the callback will be called (with body as the argument).

Method Summary

void	addForce(double fx, double fy, double fz) Add force at centre of mass of body in absolute coordinates.
void	addForce(DVector3C f) Add force at centre of mass of body in absolute coordinates.
void	addForceAtPos(double fx, double fy, double fz, double px, double py, double pz) Add force at specified point in body in global coordinates.
void	addForceAtPos(DVector3C f, DVector3C p) Add force at specified point in body in global coordinates.
void	addForceAtRelPos(double fx, double fy, double fz, double px, double py, double pz) Add force at specified point in body in local coordinates.
void	addForceAtRelPos(DVector3C f, DVector3C p) Add force at specified point in body in local coordinates.
void	addRelForce(double fx, double fy, double fz) Add force at centre of mass of body in coordinates relative to body.
void	addRelForce(DVector3C f) Add force at centre of mass of body in coordinates relative to body.
void	addRelForceAtPos(double fx, double fy, double fz, double px, double py, double pz) Add force at specified point in body in global coordinates.
void	addRelForceAtPos(DVector3C f, DVector3C p) Add force at specified point in body in global coordinates.
void	addRelForceAtRelPos(double fx, double fy, double fz, double px, double py, double pz) Add force at specified point in body in local coordinates.
void	addRelForceAtRelPos(DVector3C f, DVector3C p) Add force at specified point in body in local coordinates.
void	addRelTorque(double fx, double fy, double fz) Add torque at centre of mass of body in coordinates relative to body.
void	addRelTorque(DVector3C t) Add torque at centre of mass of body in coordinates relative to body.
void	addTorque(double fx, double fy, double fz) Add torque at centre of mass of body in absolute coordinates.
void	addTorque(DVector3C t) Add torque at centre of mass of body in absolute coordinates.
void	destroy() Destroy a body.
void	DESTRUCTOR()
void	disable() Manually disable a body.
void	enable() Manually enable a body.
double	getAngularDamping() Get the body's angular damping scale.
double	getAngularDampingThreshold() Get the body's angular damping threshold.
DVector3C	getAngularVel() Get the angular velocity of a body.
double	getAutoDisableAngularThreshold() Get auto disable angular average threshold.
int	getAutoDisableAverageSamplesCount() Get auto disable average size (samples count).
boolean	getAutoDisableFlag() Get auto disable flag.
double	getAutoDisableLinearThreshold() Get auto disable linear average threshold.
int	getAutoDisableSteps() Get auto steps a body must be thought of as idle to disable
double	getAutoDisableTime() Get auto disable time.
java.lang.Object	getData() Get the body's user-data pointer.
void	getFiniteRotationAxis(DVector3 result) Get the finite rotation axis.
boolean	getFiniteRotationMode() Get the way a body's orientation is updated each timestep.
DGeom	getFirstGeom() Deprecated. May be replaced by a more Java-like API.
DVector3C	getForce() Return the current accumulated force vector.
boolean	getGravityMode() Get whether the body is influenced by the world's gravity or not.
boolean	getGyroscopicMode() Get the body's gyroscopic state.
DJoint	getJoint(int index) Return a joint attached to this body, given by index.
double	getLinearDamping() Get the body's linear damping scale.
double	getLinearDampingThreshold() Get the body's linear damping threshold.
DVector3C	getLinearVel() Get the linear velocity of a body.
DMassC	getMass() Get the mass of a body.
double	getMaxAngularSpeed() Get the body's maximum angular speed.
DGeom	getNextGeom(DGeom geom) Deprecated. May be replaced by a more Java-like API.
int	getNumJoints() Get the number of joints that are attached to this body.
void	getPointVel(double px, double py, double pz, DVector3 result) Get velocity vector in global coords of a globally specified point on a body.
void	getPointVel(DVector3C p, DVector3 result) Get velocity vector in global coords of a globally specified point on a body.
DVector3C	getPosition() Get the position of a body.
void	getPosRelPoint(double px, double py, double pz, DVector3 result) Takes a point in global coordinates and returns the point's position in body-relative coordinates.
void	getPosRelPoint(DVector3C p, DVector3 result) Takes a point in global coordinates and returns the point's position in body-relative coordinates.
DQuaternionC	getQuaternion() Get the rotation of a body.
void	getRelPointPos(double px, double py, double pz, DVector3 result) Get world position of a relative point on body.
void	getRelPointPos(DVector3C p, DVector3 result) Get world position of a relative point on body.
void	getRelPointVel(double px, double py, double pz, DVector3 result) Get velocity vector in global coords of a relative point on body.
void	getRelPointVel(DVector3C p, DVector3 result) Get velocity vector in global coords of a relative point on body.
DMatrix3C	getRotation() Get the rotation of a body.
DVector3C	getTorque() Return the current accumulated torque vector.
DWorld	getWorld() Retrieves the world attached to the given body.
boolean	isConnectedTo(DBody body)
boolean	isEnabled() Check wether a body is enabled.
boolean	isKinematic() Check wether a body is in kinematic state.
void	setAngularDamping(double scale) Set the body's angular damping scale.
void	setAngularDampingThreshold(double threshold) Set the body's angular damping threshold.
void	setAngularVel(double x, double y, double z) Set the angular velocity of a body.
void	setAngularVel(DVector3C v) Set the angular velocity of a body.
void	setAutoDisableAngularThreshold(double threshold) Set auto disable angular average threshold.
void	setAutoDisableAverageSamplesCount(int average_samples_count) Set auto disable average buffer size (average steps).
void	setAutoDisableDefaults() Set auto disable defaults.
void	setAutoDisableFlag(boolean do_auto_disable) Set auto disable flag.
void	setAutoDisableLinearThreshold(double threshold) Set auto disable linear average threshold.
void	setAutoDisableSteps(int steps) Set auto disable steps.
void	setAutoDisableTime(double time) Set auto disable time.
void	setDamping(double linear_scale, double angular_scale) Convenience function to set linear and angular scales at once.
void	setDampingDefaults() Resets the damping settings to the current world's settings.
void	setData(java.lang.Object data) Set the body's user-data pointer.
void	setDynamic() Set rigid body to dynamic state (default).
void	setFiniteRotationAxis(double x, double y, double z) Sets the finite rotation axis for a body.
void	setFiniteRotationAxis(DVector3C a) Sets the finite rotation axis for a body.
void	setFiniteRotationMode(boolean mode) Controls the way a body's orientation is updated at each timestep.
void	setForce(double x, double y, double z) Set the body force accumulation vector.
void	setForce(DVector3C f) Set the body force accumulation vector.
void	setGravityMode(boolean mode) Set whether the body is influenced by the world's gravity or not.
void	setGyroscopicMode(boolean enabled) Enable/disable the body's gyroscopic term.
void	setKinematic() Set rigid body to kinematic state.
void	setLinearDamping(double scale) Set the body's linear damping scale.
void	setLinearDampingThreshold(double threshold) Set the body's linear damping threshold.
void	setLinearVel(double x, double y, double z) Set the linear velocity of a body.
void	setLinearVel(DVector3C v) Set the linear velocity of a body.
void	setMass(DMassC mass) Set the mass of a body.
void	setMaxAngularSpeed(double max_speed) Set the body's maximum angular speed.
void	setMovedCallback(DBody.BodyMoveCallBack callback) Set the 'moved' callback of a body.
void	setPosition(double x, double y, double z) Set position of a body.
void	setPosition(DVector3C p) Set position of a body.
void	setQuaternion(DQuaternionC q) Set the orientation of a body.
void	setRotation(DMatrix3C R) Set the orientation of a body.
void	setTorque(double x, double y, double z) Set the body torque accumulation vector.
void	setTorque(DVector3C t) Set the body torque accumulation vector.
void	vectorFromWorld(double px, double py, double pz, DVector3 result) Convert from world to local coordinates.
void	vectorFromWorld(DVector3C p, DVector3 result) Convert from world to local coordinates.
void	vectorToWorld(double px, double py, double pz, DVector3 result) Convert from local to world coordinates.
void	vectorToWorld(DVector3C p, DVector3 result) Convert from local to world coordinates.

Method Detail

DESTRUCTOR

void DESTRUCTOR()

destroy

void destroy()

Destroy a body.

Remark:

All joints that are attached to this body will be put into limbo: i.e. unattached and not affecting the simulation, but they will NOT be deleted.

setData

void setData(java.lang.Object data)

Set the body's user-data pointer.

Parameters:

data - arbitraty pointer

getData

java.lang.Object getData()

Get the body's user-data pointer.

Returns:

a pointer to the user's data.

setPosition

void setPosition(double x,
                 double y,
                 double z)

Set position of a body.

Remark:

After setting, the outcome of the simulation is undefined if the new configuration is inconsistent with the joints/constraints that are present.

setPosition

void setPosition(DVector3C p)

Set position of a body.

Remark:

After setting, the outcome of the simulation is undefined if the new configuration is inconsistent with the joints/constraints that are present.

setRotation

void setRotation(DMatrix3C R)

Set the orientation of a body.

Remark:

After setting, the outcome of the simulation is undefined if the new configuration is inconsistent with the joints/constraints that are present.

setQuaternion

void setQuaternion(DQuaternionC q)

Set the orientation of a body.

Remark:

After setting, the outcome of the simulation is undefined if the new configuration is inconsistent with the joints/constraints that are present.

setLinearVel

void setLinearVel(double x,
                  double y,
                  double z)

Set the linear velocity of a body.

setLinearVel

void setLinearVel(DVector3C v)

Set the linear velocity of a body.

setAngularVel

void setAngularVel(double x,
                   double y,
                   double z)

Set the angular velocity of a body.

setAngularVel

void setAngularVel(DVector3C v)

Set the angular velocity of a body.

getPosition

DVector3C getPosition()

Get the position of a body.

Remark:

When getting, the returned values are pointers to internal data structures, so the vectors are valid until any changes are made to the rigid body system structure.

getRotation

DMatrix3C getRotation()

Get the rotation of a body.

Returns:

pointer to a 4x3 rotation matrix.

getQuaternion

DQuaternionC getQuaternion()

Get the rotation of a body.

Returns:

pointer to 4 scalars that represent the quaternion.

getLinearVel

DVector3C getLinearVel()

Get the linear velocity of a body.

getAngularVel

DVector3C getAngularVel()

Get the angular velocity of a body.

setMass

void setMass(DMassC mass)

Set the mass of a body.

getMass

DMassC getMass()

Get the mass of a body.

getWorld

DWorld getWorld()

Retrieves the world attached to the given body.

Remark:

setAutoDisableLinearThreshold

void setAutoDisableLinearThreshold(double threshold)

Set auto disable linear average threshold.

getAutoDisableLinearThreshold

double getAutoDisableLinearThreshold()

Get auto disable linear average threshold.

Returns:

the threshold

setAutoDisableAngularThreshold

void setAutoDisableAngularThreshold(double threshold)

Set auto disable angular average threshold.

getAutoDisableAngularThreshold

double getAutoDisableAngularThreshold()

Get auto disable angular average threshold.

Returns:

the threshold

setAutoDisableSteps

void setAutoDisableSteps(int steps)

Set auto disable steps.

Parameters:

steps - the nr of steps.

getAutoDisableSteps

int getAutoDisableSteps()

Get auto steps a body must be thought of as idle to disable

Returns:

the nr of steps

setAutoDisableTime

void setAutoDisableTime(double time)

Set auto disable time.

Parameters:

time - nr of seconds.

getAutoDisableTime

double getAutoDisableTime()

Get auto disable time.

Returns:

nr of seconds

setAutoDisableFlag

void setAutoDisableFlag(boolean do_auto_disable)

Set auto disable flag.

Parameters:

do_auto_disable - 0 or 1

getAutoDisableFlag

boolean getAutoDisableFlag()

Get auto disable flag.

Returns:

0 or 1

getAutoDisableAverageSamplesCount

int getAutoDisableAverageSamplesCount()

Get auto disable average size (samples count).

Returns:

the nr of steps/size.

setAutoDisableAverageSamplesCount

void setAutoDisableAverageSamplesCount(int average_samples_count)

Set auto disable average buffer size (average steps).

Parameters:

average_samples_count - the nr of samples to review.

setAutoDisableDefaults

void setAutoDisableDefaults()

Set auto disable defaults.

Remark:

Set the values for the body to those set as default for the world.

addForce

void addForce(double fx,
              double fy,
              double fz)

Add force at centre of mass of body in absolute coordinates.

addForce

void addForce(DVector3C f)

Add force at centre of mass of body in absolute coordinates.

addTorque

void addTorque(double fx,
               double fy,
               double fz)

Add torque at centre of mass of body in absolute coordinates.

addTorque

void addTorque(DVector3C t)

Add torque at centre of mass of body in absolute coordinates.

addRelForce

void addRelForce(double fx,
                 double fy,
                 double fz)

Add force at centre of mass of body in coordinates relative to body.

addRelForce

void addRelForce(DVector3C f)

Add force at centre of mass of body in coordinates relative to body.

addRelTorque

void addRelTorque(double fx,
                  double fy,
                  double fz)

Add torque at centre of mass of body in coordinates relative to body.

addRelTorque

void addRelTorque(DVector3C t)

Add torque at centre of mass of body in coordinates relative to body.

addForceAtPos

void addForceAtPos(double fx,
                   double fy,
                   double fz,
                   double px,
                   double py,
                   double pz)

Add force at specified point in body in global coordinates.

addForceAtPos

void addForceAtPos(DVector3C f,
                   DVector3C p)

Add force at specified point in body in global coordinates.

addForceAtRelPos

void addForceAtRelPos(double fx,
                      double fy,
                      double fz,
                      double px,
                      double py,
                      double pz)

Add force at specified point in body in local coordinates.

addForceAtRelPos

void addForceAtRelPos(DVector3C f,
                      DVector3C p)

Add force at specified point in body in local coordinates.

addRelForceAtPos

void addRelForceAtPos(double fx,
                      double fy,
                      double fz,
                      double px,
                      double py,
                      double pz)

Add force at specified point in body in global coordinates.

addRelForceAtPos

void addRelForceAtPos(DVector3C f,
                      DVector3C p)

Add force at specified point in body in global coordinates.

addRelForceAtRelPos

void addRelForceAtRelPos(double fx,
                         double fy,
                         double fz,
                         double px,
                         double py,
                         double pz)

Add force at specified point in body in local coordinates.

addRelForceAtRelPos

void addRelForceAtRelPos(DVector3C f,
                         DVector3C p)

Add force at specified point in body in local coordinates.

getForce

DVector3C getForce()

Return the current accumulated force vector.

Returns:

points to an array of 3 reals.

Remark:

The returned values are pointers to internal data structures, so the vectors are only valid until any changes are made to the rigid body system.

getTorque

DVector3C getTorque()

Return the current accumulated torque vector.

Returns:

points to an array of 3 reals.

Remark:

The returned values are pointers to internal data structures, so the vectors are only valid until any changes are made to the rigid body system.

setForce

void setForce(double x,
              double y,
              double z)

Set the body force accumulation vector.

Remark:

This is mostly useful to zero the force and torque for deactivated bodies before they are reactivated, in the case where the force-adding functions were called on them while they were deactivated.

setForce

void setForce(DVector3C f)

Set the body force accumulation vector.

Remark:

This is mostly useful to zero the force and torque for deactivated bodies before they are reactivated, in the case where the force-adding functions were called on them while they were deactivated.

setTorque

void setTorque(double x,
               double y,
               double z)

Set the body torque accumulation vector.

Remark:

This is mostly useful to zero the force and torque for deactivated bodies before they are reactivated, in the case where the force-adding functions were called on them while they were deactivated.

setTorque

void setTorque(DVector3C t)

Set the body torque accumulation vector.

Remark:

This is mostly useful to zero the force and torque for deactivated bodies before they are reactivated, in the case where the force-adding functions were called on them while they were deactivated.

getRelPointPos

void getRelPointPos(double px,
                    double py,
                    double pz,
                    DVector3 result)

Get world position of a relative point on body.

Parameters:

result - will contain the result.

getRelPointPos

void getRelPointPos(DVector3C p,
                    DVector3 result)

Get world position of a relative point on body.

Parameters:

result - will contain the result.

getRelPointVel

void getRelPointVel(double px,
                    double py,
                    double pz,
                    DVector3 result)

Get velocity vector in global coords of a relative point on body.

Parameters:

result - will contain the result.

getRelPointVel

void getRelPointVel(DVector3C p,
                    DVector3 result)

Get velocity vector in global coords of a relative point on body.

Parameters:

result - will contain the result.

getPointVel

void getPointVel(double px,
                 double py,
                 double pz,
                 DVector3 result)

Get velocity vector in global coords of a globally specified point on a body.

Parameters:

result - will contain the result.

getPointVel

void getPointVel(DVector3C p,
                 DVector3 result)

Get velocity vector in global coords of a globally specified point on a body.

Parameters:

result - will contain the result.

getPosRelPoint

void getPosRelPoint(double px,
                    double py,
                    double pz,
                    DVector3 result)

Takes a point in global coordinates and returns the point's position in body-relative coordinates.

Parameters:

result - will contain the result.

Remark:

This is the inverse of dBodyGetRelPointPos()

getPosRelPoint

void getPosRelPoint(DVector3C p,
                    DVector3 result)

Takes a point in global coordinates and returns the point's position in body-relative coordinates.

Parameters:

result - will contain the result.

Remark:

This is the inverse of dBodyGetRelPointPos()

vectorToWorld

void vectorToWorld(double px,
                   double py,
                   double pz,
                   DVector3 result)

Convert from local to world coordinates.

Parameters:

result - will contain the result.

vectorToWorld

void vectorToWorld(DVector3C p,
                   DVector3 result)

Convert from local to world coordinates.

Parameters:

result - will contain the result.

vectorFromWorld

void vectorFromWorld(double px,
                     double py,
                     double pz,
                     DVector3 result)

Convert from world to local coordinates.

Parameters:

result - will contain the result.

vectorFromWorld

void vectorFromWorld(DVector3C p,
                     DVector3 result)

Convert from world to local coordinates.

Parameters:

result - will contain the result.

setFiniteRotationMode

void setFiniteRotationMode(boolean mode)

Controls the way a body's orientation is updated at each timestep.

Parameters:

mode - can be 0 or 1:

0: An ``infinitesimal'' orientation update is used. This is fast to compute, but it can occasionally cause inaccuracies for bodies that are rotating at high speed, especially when those bodies are joined to other bodies. This is the default for every new body that is created.

1: A ``finite'' orientation update is used. This is more costly to compute, but will be more accurate for high speed rotations.

Remark:

Note however that high speed rotations can result in many types of error in a simulation, and the finite mode will only fix one of those sources of error.

setFiniteRotationAxis

void setFiniteRotationAxis(double x,
                           double y,
                           double z)

Sets the finite rotation axis for a body.

Remark:

This is axis only has meaning when the finite rotation mode is set If this axis is zero (0,0,0), full finite rotations are performed on the body. If this axis is nonzero, the body is rotated by performing a partial finite rotation along the axis direction followed by an infinitesimal rotation along an orthogonal direction., This can be useful to alleviate certain sources of error caused by quickly spinning bodies. For example, if a car wheel is rotating at high speed you can call this function with the wheel's hinge axis as the argument to try and improve its behavior.

setFiniteRotationAxis

void setFiniteRotationAxis(DVector3C a)

Sets the finite rotation axis for a body.

Remark:

This is axis only has meaning when the finite rotation mode is set If this axis is zero (0,0,0), full finite rotations are performed on the body. If this axis is nonzero, the body is rotated by performing a partial finite rotation along the axis direction followed by an infinitesimal rotation along an orthogonal direction., This can be useful to alleviate certain sources of error caused by quickly spinning bodies. For example, if a car wheel is rotating at high speed you can call this function with the wheel's hinge axis as the argument to try and improve its behavior.

getFiniteRotationMode

boolean getFiniteRotationMode()

Get the way a body's orientation is updated each timestep.

Returns:

the mode 0 (infitesimal) or 1 (finite).

getFiniteRotationAxis

void getFiniteRotationAxis(DVector3 result)

Get the finite rotation axis.

Parameters:

result - will contain the axis.

getNumJoints

int getNumJoints()

Get the number of joints that are attached to this body.

Returns:

nr of joints

getJoint

DJoint getJoint(int index)

Return a joint attached to this body, given by index.

Parameters:

index - valid range is 0 to n-1 where n is the value returned by dBodyGetNumJoints().

setDynamic

void setDynamic()

Set rigid body to dynamic state (default).

setKinematic

void setKinematic()

Set rigid body to kinematic state. When in kinematic state the body isn't simulated as a dynamic body (it's "unstoppable", doesn't respond to forces), but can still affect dynamic bodies (e.g. in joints). Kinematic bodies can be controlled by position and velocity.

Note:

A kinematic body has infinite mass. If you set its mass to something else, it loses the kinematic state and behaves as a normal dynamic body.

isKinematic

boolean isKinematic()

Check wether a body is in kinematic state.

Returns:

1 if a body is kinematic or 0 if it is dynamic.

enable

void enable()

Manually enable a body.

disable

void disable()

Manually disable a body.

Remark:

A disabled body that is connected through a joint to an enabled body will be automatically re-enabled at the next simulation step.

isEnabled

boolean isEnabled()

Check wether a body is enabled.

Returns:

1 if a body is currently enabled or 0 if it is disabled.

setGravityMode

void setGravityMode(boolean mode)

Set whether the body is influenced by the world's gravity or not.

Parameters:

mode - when nonzero gravity affects this body.

Remark:

Newly created bodies are always influenced by the world's gravity.

getGravityMode

boolean getGravityMode()

Get whether the body is influenced by the world's gravity or not.

Returns:

nonzero means gravity affects this body.

isConnectedTo

boolean isConnectedTo(DBody body)

getLinearDamping

double getLinearDamping()

Get the body's linear damping scale.

setLinearDamping

void setLinearDamping(double scale)

Set the body's linear damping scale.

Parameters:

scale - The linear damping scale. Should be in the interval [0, 1].

See Also:

setDampingDefaults()

Remark:

From now on the body will not use the world's linear damping scale until dBodySetDampingDefaults() is called.

getAngularDamping

double getAngularDamping()

Get the body's angular damping scale.

Remark:

If the body's angular damping scale was not set, this function returns the world's angular damping scale.

setAngularDamping

void setAngularDamping(double scale)

Set the body's angular damping scale.

Parameters:

scale - The angular damping scale. Should be in the interval [0, 1].

Remark:

From now on the body will not use the world's angular damping scale until dBodyResetAngularDamping() is called.

setDamping

void setDamping(double linear_scale,
                double angular_scale)

Convenience function to set linear and angular scales at once.

Parameters:

linear_scale - The linear damping scale. Should be in the interval [0, 1].

angular_scale - The angular damping scale. Should be in the interval [0, 1].

See Also:

setLinearDamping(double), setAngularDamping(double)

getLinearDampingThreshold

double getLinearDampingThreshold()

Get the body's linear damping threshold.

setLinearDampingThreshold

void setLinearDampingThreshold(double threshold)

Set the body's linear damping threshold.

Parameters:

threshold - The linear threshold to be used. Damping is only applied if the linear speed is above this limit.

getAngularDampingThreshold

double getAngularDampingThreshold()

Get the body's angular damping threshold.

setAngularDampingThreshold

void setAngularDampingThreshold(double threshold)

Set the body's angular damping threshold.

Parameters:

threshold - The angular threshold to be used. Damping is only used if the angular speed is above this limit.

setDampingDefaults

void setDampingDefaults()

Resets the damping settings to the current world's settings.

getMaxAngularSpeed

double getMaxAngularSpeed()

Get the body's maximum angular speed.

See Also:

DWorld.getMaxAngularSpeed()

setMaxAngularSpeed

void setMaxAngularSpeed(double max_speed)

Set the body's maximum angular speed.

See Also:

DWorld.setMaxAngularSpeed(double)

getGyroscopicMode

boolean getGyroscopicMode()

Get the body's gyroscopic state.

Returns:

nonzero if gyroscopic term computation is enabled (default), zero otherwise.

setGyroscopicMode

void setGyroscopicMode(boolean enabled)

Enable/disable the body's gyroscopic term. Disabling the gyroscopic term of a body usually improves stability. It also helps turning spining objects, like cars' wheels.

Parameters:

enabled - nonzero (default) to enable gyroscopic term, 0 to disable.

setMovedCallback

void setMovedCallback(DBody.BodyMoveCallBack callback)

Set the 'moved' callback of a body. Whenever a body has its position or rotation changed during the timestep, the callback will be called (with body as the argument). Use it to know which body may need an update in an external structure (like a 3D engine).

Parameters:

callback - the callback to be invoked when the body moves. Set to zero to disable.

getFirstGeom

DGeom getFirstGeom()

Deprecated. May be replaced by a more Java-like API.

Return the first geom associated with the body. You can traverse through the geoms by repeatedly calling dBodyGetNextGeom().

Returns:

the first geom attached to this body, or 0.

getNextGeom

DGeom getNextGeom(DGeom geom)

Deprecated. May be replaced by a more Java-like API.

Returns the next geom associated with the same body.

Parameters:

geom - a geom attached to some body.

Returns:

the next geom attached to the same body, or 0.

See Also:

getFirstGeom()